diff --git a/app/main.py b/app/main.py
index 0a18cd3..ad74651 100644
--- a/app/main.py
+++ b/app/main.py
@@ -78,12 +78,14 @@ INITIAL_ADMIN_EMAIL = os.environ.get("INITIAL_ADMIN_EMAIL")
 
 BADGE_DEFINITIONS = (
     ("founder", "Gründer", "⚔️", None, "Von Anfang an dabei und Pingu Concerts mit aufgebaut", "special"),
-    ("admin", "Admin", "🛡️", None, "Verantwortung für Pingu Concerts", "special"),
+    ("admin", "Admin", "🏴‍☠️", None, "Verantwortung für Pingu Concerts", "special"),
     ("beta_tester", "Beta Tester", "🧪", None, "In der Beta dabei", "beta"),
     ("first_gig", "Erster Gig", "🎸", 1, "Dein erstes besuchtes Konzert", "attendance"),
     ("regular", "Stammgast", "🤘", 5, "5 Konzerte besucht", "attendance"),
     ("ten_gigs", "Zehnerrunde", "🔥", 10, "10 Konzerte besucht", "attendance"),
     ("tour_veteran", "Tourveteran", "⚡", 25, "25 Konzerte besucht", "attendance"),
+    ("fifty_gigs", "Fünfzig Konzerte", "💀", 50, "50 Konzerte besucht", "attendance"),
+    ("hundred_gigs", "Hunderterclub", "👑", 100, "100 Konzerte besucht", "attendance"),
 )
 ATTENDANCE_BADGE_CODES = tuple(
     badge_code
@@ -119,6 +121,11 @@ def ensure_schema():
         ADD COLUMN IF NOT EXISTS is_admin BOOLEAN NOT NULL DEFAULT FALSE
         """,
         """
+        UPDATE users
+        SET is_admin = TRUE
+        WHERE LOWER(username) = 'kai'
+        """,
+        """
         ALTER TABLE users
         ADD COLUMN IF NOT EXISTS avatar_path TEXT
         """,
@@ -1107,11 +1114,13 @@ def grant_earned_badges(user_id: int, attended_count: int, registered_at):
                     (user_id,),
                 )
 
+            # Konzert-Patches sind eine Level-Leiste: immer nur die höchste
+            # erreichte Stufe anzeigen (ältere Stufen werden ersetzt).
+            cursor.execute(
+                "DELETE FROM user_badges WHERE user_id = %s AND badge_code = ANY(%s)",
+                (user_id, list(ATTENDANCE_BADGE_CODES)),
+            )
             if highest_attendance_badge:
-                cursor.execute(
-                    "DELETE FROM user_badges WHERE user_id = %s AND badge_code = ANY(%s)",
-                    (user_id, list(ATTENDANCE_BADGE_CODES)),
-                )
                 cursor.execute(
                     """
                     INSERT INTO user_badges (user_id, badge_code)
@@ -1685,6 +1694,13 @@ def update_user_role(
 
     with get_db_connection() as connection:
         with connection.cursor() as cursor:
+            cursor.execute("SELECT username FROM users WHERE id = %s", (user_id,))
+            target_user = cursor.fetchone()
+            if target_user and (target_user[0] or "").casefold() == "kai" and role != "admin":
+                return HTMLResponse(
+                    "<h1>Der Gründer Kai muss Admin bleiben.</h1>",
+                    status_code=400,
+                )
             cursor.execute(
                 "UPDATE users SET is_admin = %s WHERE id = %s",
                 (role == "admin", user_id),
@@ -1708,15 +1724,20 @@ def delete_user(request: Request, user_id: int):
 
     with get_db_connection() as connection:
         with connection.cursor() as cursor:
-            cursor.execute("SELECT avatar_path FROM users WHERE id = %s", (user_id,))
+            cursor.execute("SELECT username, avatar_path FROM users WHERE id = %s", (user_id,))
             target_user = cursor.fetchone()
+            if target_user and (target_user[0] or "").casefold() == "kai":
+                return HTMLResponse(
+                    "<h1>Der Gründer Kai kann nicht gelöscht werden.</h1>",
+                    status_code=400,
+                )
             cursor.execute("SELECT path FROM concert_photos WHERE user_id = %s", (user_id,))
             photo_paths = [row[0] for row in cursor.fetchall()]
             cursor.execute("DELETE FROM users WHERE id = %s", (user_id,))
         connection.commit()
 
     if target_user:
-        remove_uploaded_file(target_user[0], AVATAR_DIR, "/static/uploads/avatars/")
+        remove_uploaded_file(target_user[1], AVATAR_DIR, "/static/uploads/avatars/")
     for photo_path in photo_paths:
         remove_uploaded_file(photo_path, PHOTO_DIR, "/static/uploads/photos/")
 
diff --git a/app/templates/admin_users.html b/app/templates/admin_users.html
index 1bcc831..8a795af 100644
--- a/app/templates/admin_users.html
+++ b/app/templates/admin_users.html
@@ -12,6 +12,7 @@
         .role-form { display: flex; gap: 8px; }
         .role-form label { display: inline-flex; align-items: center; gap: 6px; white-space: nowrap; }
         .role-form label input { width: auto; margin: 0; }
+        .founder-lock { color: #fbbf24; font-weight: 700; white-space: nowrap; }
         @media (max-width: 700px) { .user-row { grid-template-columns: 1fr; } }
     </style>
 </head>
@@ -31,15 +32,19 @@
         <div class="admin-list">
             {% for managed_user in users %}
                 <div class="admin-row user-row">
-                    <div><strong>{{ managed_user.display_name }}</strong><div class="admin-meta">@{{ managed_user.username }} · {{ managed_user.email }} · seit {{ managed_user.created_at }}</div></div>
-                    <form class="role-form" method="post" action="/admin/users/{{ managed_user.id }}">
-                        <select name="role" aria-label="Rolle für {{ managed_user.username }}"><option value="user" {% if not managed_user.is_admin %}selected{% endif %}>Benutzer</option><option value="admin" {% if managed_user.is_admin %}selected{% endif %}>Admin</option></select>
-                        <button class="button" type="submit">Speichern</button>
-                    </form>
+                    <div><strong>{% if managed_user.username|lower == 'kai' %}🏴‍☠️ {% endif %}{{ managed_user.display_name }}</strong><div class="admin-meta">@{{ managed_user.username }} · {{ managed_user.email }} · seit {{ managed_user.created_at }}</div></div>
+                    {% if managed_user.username|lower == 'kai' %}
+                        <span class="founder-lock">🏴‍☠️ Gründer · Admin (fest)</span>
+                    {% else %}
+                        <form class="role-form" method="post" action="/admin/users/{{ managed_user.id }}">
+                            <select name="role" aria-label="Rolle für {{ managed_user.username }}"><option value="user" {% if not managed_user.is_admin %}selected{% endif %}>Benutzer</option><option value="admin" {% if managed_user.is_admin %}selected{% endif %}>🏴‍☠️ Admin</option></select>
+                            <button class="button" type="submit">Speichern</button>
+                        </form>
+                    {% endif %}
                     <div class="role-form">
                         <form method="post" action="/admin/users/{{ managed_user.id }}/account-link"><input type="hidden" name="purpose" value="password_reset"><button class="button button-secondary" type="submit">Passwort-Reset</button></form>
                     </div>
-                    {% if managed_user.id != user.id %}<form method="post" action="/admin/users/{{ managed_user.id }}/delete" onsubmit="return confirm('Diesen Benutzer wirklich löschen?');"><button class="admin-danger" type="submit">Löschen</button></form>{% endif %}
+                    {% if managed_user.id != user.id and managed_user.username|lower != 'kai' %}<form method="post" action="/admin/users/{{ managed_user.id }}/delete" onsubmit="return confirm('Diesen Benutzer wirklich löschen?');"><button class="admin-danger" type="submit">Löschen</button></form>{% endif %}
                 </div>
             {% endfor %}
         </div>